An important aspect of \(\mathbf {F}_c\)  is the choice of basis function \(\mathbf {B}: \mathbb {R}^E \rightarrow \mathbb {R}^B\)  that transforms the raw distance features \(\mathbf {e}_{st}\)  into ones that are more discriminative. Several choices of basis functions have been proposed, such as a Gaussian over 1D distances [1]} and a spherical Bessel function over the joint 2D space of the edge distance and angle [2]}. We extend these ideas to capture the full 3D positional differences between atoms, and systematically study the effectiveness of different basis functions in the context of a force-centric model.
